The need for improvements in lead-acid storage batteries is widely recognized.
Hundreds of articles, patents and research projects have been directed toward improving such batteries. Some of the important characteristics that still need improvement are power density, mechanical ruggedness, long life and multiple cycles (charge-discharge). Some important uses for such improved batteries are in “start stop” cars and electric cars (EV) and plug-in hybrid cars (PHEV).
It is generally believed that automobile batteries have a lifetime of 3, or at most 6, years and that to have longer life they should have thicker lead positive grids. In contrast, the present invention intends to provide a 10 year lifetime battery using positive grids.
It has been suggested that the power or lifetime of lead acid batteries may be increased by substituting lead plates (grids) with other materials. However, it is believed that almost all commercially available lead acid batteries use lead plates. There are now a number of projects that have been reported to use non-metal battery plates. Firefly Energy has announced it is developing carbon foam plates, see U.S. Pat. Nos. 6,979,513 and 7,033,703. Also, Jung et al have filed patent applications on carbon battery plates, see U.S. applications Ser. Nos. 11/048,104 and 11/279,103 (both now abandoned).
Axion Power now has eight issued U.S. patents covering various aspects of its PbC (lead-carbon) hybrid battery grid technologies. They are: U.S. Pat. No. 6,466,429—Electric double layer capacitor; U.S. Pat. No. 6,628,504—Electric double layer capacitor; U.S. Pat. No. 6,706,079—Formation and charge of the negative polarizable carbon electrode in an electric double layer capacitor; U.S. Pat. No. 7,006,346 Positive Electrode of an electric double layer capacitor; U.S. Pat. No. 7,110,242—Electrode for electric double layer capacitor; U.S. Pat. No. 7,119,047 and U.S. Pat. No. 7,569,514—Modified activated carbon; U.S. Pat. No. 7,881,042—Activated Carbon Electrode with PTFE Binder.
CSIRO (Commonwealth Scientific & Industrial Research Organization—AU) has announced its “ Ultra-Battery”, a hybrid battery related to U.S. Pat. No. 7,929,151.
One suggestion is to use lead electroplated on a core of another metal, such as aluminum, copper, steel or titanium. Some of the prior patents and articles about lead-plated cores, or otherwise relevant, are set forth below. All of these patents and articles, and all others cited in this patent application, are included herein by reference. A series of patents to Rubin uses expanded titanium or titanium alloy positive grids without a lead coating. In U.S. Pat. No. 3,486,940 Rubin discloses a titanium nitride core with a gold covering layer; in U.S. Pat. No. 3,615,831 he discloses a similar gold covering layer over a titanium-molybdenum-zirconium alloy core and in U.S. Pat. No. 4,251,608 he discloses a steel or titanium core with a graphite protective coating. See also Rubin U.S. Pat. Nos. 3,798,070 and 3,870,563 and Will U.S. Pat. No. 4,326,017.
Lead is plated on copper in Senoo U.S. Pat. No. 5,223,354; Senoo U.S. Pat. No. 5,093,970; Nann U.S. Pat. No. 4,760,001 and Kiessling U.S. Pat. No. 4,554,228 and U.S. Pat. No. Re.:33,133. U.S. Pat. No. 4,683,648 to Yeh shows a titanium core electroplated with lead. U.S. Pat. Nos. 5,379,502; 5,339,873; 5,544,681 and 5,411,821 disclose copper or steel or other materials as cores with titanium and lead layers. U.S. Pat. No. 6,316,148 to Bhardwaj discloses a battery using aluminum foil which is coated with lead. U.S. Pat. Nos. 2,739,997 and 2,713,079 to Carrick disclose aluminum plates electroplated with lead in an aqueous plating bath.
The following articles may be considered relevant: Dai et al. “Lead-plated titanium grids etc.” 41 Power Sources Conference, Jun. 14-17 (2004) and Dai et al. “ Corrosion of Lead Plate Titanium etc” (ref. Google).